IVo DISCUSSION 

 lo Floristics . 



a. General , Poaceae (grass family) was represented by the most 

 species, making up 19 percent of the total florae The Asteraceae 

 (daisy family) made up 16 percent and Cyperaceae (sedge family) 8 

 percent. The remaining families represent 2 percent or less of the 

 total flora. This compares with Burk's (1968) figures for the total 

 Outer Banks of 14.7 percent for the Poaceae and 13.5 percent for the 

 Asteraceae. 



Among the species collected, Radford, Ahles, and Bell (1964) cited 

 five as infrequent, three as rare, and one as very rare. The infrequent 

 plants were Lilaeopsis aarolinensis , Eupatoriwn serotinum (throughwort) , 

 Heterotheaa adenolepis, Desmodiim pauoiflorum (beggar lice), and Staohys 

 nuttallii (hedge nettle). The rare species were Eragrostis eltiottii 

 (love grass), P. covarulum, and A. breviligulata. The A. breviligulata 

 is locally very abundant at Duck due to plantings. Cyperus suvinamensis 

 was noted as very rare. This species was represented by a large clump 

 of individuals near the edge of the sound in the extreme southeastern 

 part of the study area. 



b. Triplasis purpurea . This species was the most frequent plant 

 in areas of moderate sand drift which suggests that it may have 

 importance as a secondary soil stabilizer. If this is the case, this 

 species, an annual, must show salt-spray tolerance and function as a 

 soil binder even during the winter when it is dead. 



Seed and seedling tolerance to salt and the effect of cold 

 treatment on seed germination was studied. The seedlings exhibited 

 a high tolerance to both a salty substratum and to salt spray. Seed 

 tolerance was as great as that of U. panioulata and Ao breviligulata, 

 the two most important primary dune stabilizers on the Outer Banks 

 (Seneca, 1969) . 



Observations- made during the winter of 1974-75 indicate that when 

 this species occurs in abundance, as in the sandgrass-buttonweed 

 community, it acts to stabilize sandy areas during the winter months. 

 The usefulness of this species as a sand binder should be carefully 

 evaluated with appropriate test plantings. 



2. Vegetational Studies . 



The plant communities at the Duck Field Research Facility exist 

 because of the natural environmental forces characteristic of the 

 Outer Banks and a long history of disturbance. Some types of 

 disturbance are common to the Outer Banks in general, others are 

 unique to this site, e.g., its use as a gunnery range. 



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